In general, an endoscope includes an operation section that an operator grasps to perform various kinds of operation and an insertion section. The insertion section includes a flexible portion that is a slim tube extended from the operation section and has flexibility, a bending portion that is continuously provided to a distal end of the flexible portion and is bendable in a left and right or an up and down direction, and a rigid distal end portion that is continuously provided to a distal end of the bending portion. The operator inserts the insertion portion into a body cavity per anus, per os, or per naso, observes and diagnoses a predetermined region, or performs treatment or the like while observing the region.
Incidentally, to inert the insertion section of the endoscope into the body cavity, in the past, a method of pushing in the insertion portion of the endoscope by applying a force to the insertion portion from the outside of the body of a patient is adopted.
However, in such a push-in method, when the insertion portion is inserted into a large intestine or a small intestine per anus or per os, it may be difficult to smoothly perform the insertion as described below.
Intestinal tracts of the large intestine, the small intestine, and the like are small in a tube cavity inner diameter, long, and complexly wind and, moreover, are not firmly fixed, and are flexible. Therefore, even if the operator moves or compresses the insertion section of the endoscope in a moving direction by pushing in the insertion section, when the operator releases the push-in force, the insertion section is pushed back to nearly an original position by a reaction. Therefore, the insertion section does not easily advance in the moving direction and, in particular, in the depth of the intestinal tract, the insertion section is conspicuously pushed back. When the insertion section is inserted into the depth, in particular, an inspection time is long and insertion work of the insertion section is difficult.
Therefore, in order to make it possible to insert the insertion section of the endoscope into the intestinal tract without pushing in the insertion section by applying a force thereto from the outside of the body of the patient, as a first prior example, an endoscope insertion support tool is disclosed in Japanese Patent Application Laid-Open No. 59-181121.
The endoscope insertion support tool in the first prior example has a balloon that is inflated and deflated by injection and discharge of a fluid at a distal end of a slim tube having flexibility. A fluid outflow and inflow device that injects and discharges the fluid into and out of the balloon for inflation and deflation is connectable to a rear end of the tube. An operator inserts the endoscope insertion support tool into a forceps channel of an endoscope from a side close to the operator, causes the balloon to project from a distal end of the endoscope and allows the balloon to move close to and away from the distal end. The operator holds and releases the intestinal tract by inflating and deflating the balloon and inserts the endoscope into the depth.
As a second prior example, in Japanese Patent Application Laid-Open No. 8-299261, a balloon that is inflated in a radial direction of an insertion section of an endoscope is provided on an outer peripheral surface of an endoscope tube equivalent to the insertion section. The balloon is provided to be capable of advancing and retracting on the outer peripheral surface of the endoscope tube by a feed screw mechanism arranged in the endoscope tube. In the endoscope tube, a flexible air tube that supplies the air to the balloon is disposed. The balloon is inflated and deflated by an air pressure regulator.
However, in the endoscope insertion support tool in the first prior example, since the balloon has to be fully inserted through the forceps channel of the endoscope, in reality, only a small balloon can be attached. Therefore, a holding force for the intestinal tract is small when the balloon is inflated. Since the holding force is small in this way, the intestinal tract tends to shift in a state in which the intestinal tract should be held. It is extremely difficult to move the endoscope forward into the depth of the intestinal tract.
In the endoscope in the second prior example, since an advancing and retraction amount of the balloon depends on a size of an opening hole opened on the outside of the endoscope tube, a movement amount of the balloon for moving the endoscope forward is limited. Therefore, it takes time to insert the endoscope.
In the second prior example, since the balloon is provided further on a proximal end portion side than the distal end portion of the endoscope, the balloon prevents the insertion in a visual field direction. Thus, it is impossible to grasp the bent intestinal tract, remove the bend, and check a state of the intestinal tract in inserting the endoscope in the visual field direction. Since it is impossible to check the state of the intestinal tract in this way, it is difficult to smoothly insert the endoscope into the depth of the intestinal tract.
The present invention has been devised in view of the points described above and it is an object of the present invention to provide an endoscope insertion support tool and an endoscope device that can smoothly insert, in inserting an insertion section of an endoscope into a tube cavity of a large intestine, a small intestine, or the like, for example, per anus or per os, the insertion section to a depth side and can attain a reduction in an inspection time and the like.